The present invention relates to an apparatus for the automatic harvesting of fruit such as olives, nuts, almonds and/or the like.
Today, due to obvious economical reasons, the harvesting of fruit, and particularly of olives, is carried out mechanically by means of apparatuses which, based on the tree shaking method, may generally classified into two principal types. The first and more conventional one comprises a device which shakes the branches to detach the fruit therefrom, by means of unidirectional reciprocating movements. This shaking method may often cause damages to the tree and moreover it is not able to provide a high harvesting efficiency.
The second type of apparatus comprises a vibrating device which, after catching the tree or branches thereof, by means of jaw members, transmits the power of a motor to the tree by means of repeated vibrations having a high-value fixed frequency (for example, 4000 cycles per minute). In this manner very small shock waves are successively produced which generate a high frequency pulsation the direction of which changes continuously through a 360.degree. arc, said vibration increasing from the largest branches to the smallest ones. Therefore, the fruit detaches due to composite effects caused by resonance and by such residual torsional couples which concentrate prevailingly onto the fruit stem, the possibility of damaging the tree being in this manner greatly reduced.
However, even the known apparatuses of the vibration type are not completely satisfactory principally due to the impossibility of varying during operation not only the vibration frequency of the vibrating device but also other parameters of the vibration. Moreover, in the known apparatuses of the vibration type for harvesting fruit, the mechanism for the closing and/or opening operations of the jaw or catching members of the vibrating device presents some disadvantages in that its operation requires generally a high power and further introduces excessive stresses to structural elements of said vibrating device, which often cause the arms, catching jaws or carrying structure to break.